Quiz #326 (2009-4-08) Answer

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Answer by Tony Leukering

An obvious shorebird, with some important bits invisible: yet another typical Mr. Bill Mystery Quiz. The fuzziness of the picture might not help, either. A first task, after (of course) getting to shorebirds, might be to decide whether it's a larger one or a smaller one. As noted by a couple of respondents, the bird's proportions -- large, chunky body, thin neck, apparently smallish head -- should rule out the peeps (and isn't it nice to not have to deal with the Least Sandpiper/Long-toed Stint dichotomy!) and suggest a larger shorebird of some type. Though many birders would not even try to ID this bird in this posture, we've actually got a lot to go on and can quickly whittle things down to just a few options.

First, there aren't many larger shorebirds with such yellow legs and one of the usual large, buffy shorebirds that comes to mind, Marbled Godwit, is easily ruled out by the leg color. In fact, just utilizing leg color and overall color tone, we might consider only Pectoral, Sharp-tailed, Buff-breasted, and Stilt sandpipers; Ruff; and Wilson's Phalarope. We can quickly rule out Buff-breasted Sandpiper and Wilson's Phalarope, as those two species do not probe, but pick bits of food from the water's surface and/or land. Additional plumage features rule these two species out: lack of black spots at shoulder and dark-centered, rather than gray-centered, scapulars, among others.

Hopefully, no one would confuse our quiz bird with an adult Stilt Sandpiper, but some juvs can be this buffy and the species should be considered. Oops, we should already have considered age! The plethora of buff feather fringes should be all we need to decide that our bird is a juvenile, unless its a Ruff, as some adults sport such fringes, too. But, such birds would not have such a buffy throat and neck, so, regardless, our bird is a juvenile. At this point, we should, perhaps, throw Short-billed Dowitcher into the mix.

Returning to Stilt Sandpiper, even the buffiest-bodied juvs would sport white-fringed lower scapulars. Also, even with much of the bird's head in the water, we see enough of it to see that Stilt Sandpiper's obvious whitish superciliary is not present. Also, the legs have just too much orange aspect for that species. Despite tossing Short-billed Dowitcher into the mix in the previous paragraph, I'm going to quickly throw it back out, as our quiz bird lacks that species' whitish superciliary and would sport more and more-obvious internal markings on the scapulars and tertials.

Sharp-tailed Sandpiper should sport a quite-reddish crown and more-reddish feather fringes on the top side. Pectoral Sandpiper exhibits stronger blackish streaking on the throat and chest than does our quiz bird.

Whoa, lo and behold, we've eliminated all possibilities but one. Sean Fitzgerald took this week's quiz photo of a juvenile Ruff at Edwin B. Forsythe (Brigantine) N.W.R., Atlantic Co., NJ, on 8 October 2008.

One of the incorrect responses would have been considered precluded from being correct for the competition if it had been correct, as it included one too few hyphens and one too many capital letters.

Incorrect species provided as answers:
Sharp-tailed Sandpiper - 1
Buff-breasted Sandpiper - 2
Wilson's Phalarope - 2
Long-billed Dowitcher - 1
Stilt Sandpiper - 4

The 14 of 24 providing the correct answer:
John Bissell
Mark Dettling
Peter Wilkinson
Al Guarente
Peter Burke
Kevin Kerr
Nick Komar
Ira Sanders
Tammy Sanders
Marcel Such
Joe Bens
Tucker Lutter
Robert McNab
Joel Such

Answer: Ruff

Quiz #325 (2009-4-07) Answer

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Answer by Kevin Kerr and Tony Leukering

Wow, lots of birds in this quiz picture! And, with my rep, folks probably spent a lot of time sorting through the birds looking for something hidden amongst all of the Brown-headed Cowbirds. Kevin Kerr sent in another thorough answer, so he will do most of the job of answering this week's quiz.

"Uh oh! It's another one of those pictures. Where's Waldo? The flock is quite sizable this time and more intimidating than say, terns on a dock, or snakes on a plane. I decided that it's time to model a new approach to these pictures, though I suppose this is just a classic approach to identifying large flocks. First, identify an obvious bird, one displaying a good diagnostic profile. Two birds in flight do this nicely: clearly male Brown-headed Cowbirds. A few of their drabber female companions are also in clear view. In fact, at quick glance it appears that most if not all of these birds are Brown-headed Cowbirds. So, now we have a null hypothesis for each individual: it's a Brown-headed Cowbird until proven otherwise.

"But there's got to be more than that, right? Judging by the yellowing plants in the background and fallen leaves, I'm assuming this picture was taken in autumn. Naturally, cowbird flocks are likely to contain other Icterids, so it would be wise to look for such. Any tiger-barred bodies out there? Any bronzed feathers or keel-shaped tails? To the far left, it looks as though a yellow-bordered epaulet is peeking out of the crowd, but alas I think it is just an illusion caused by a blade of grass and not a Red-winged Blackbird. A small brown job facing us in the centre of the photo could be mistaken for a female House Sparrow, but most of the colours aren't right and again, it appears to just be my imagination. Now I'm trying too hard to see species that probably are not there.

"Negative results are inherently difficult to prove, but I cannot find a bird in this photo that displays enough cues to suggest that it is not a Brown-headed Cowbird. So I'll have to conclude that there are no other species present."

Thanks, Kevin. Both of the birds that Kevin mentioned that might be something else (and I thought that if they were something else, they would both be Red-winged Blackbirds), are birds that I noted when looking at the original picture considering whether to use it as a quiz picture as I had intended when I took the picture. In the field, the flock was about 1100 birds strong (this picture depicts only a small percentage of the total flock). There were six Red-winged Blackbirds in the flock, along with a very small smattering of European Starlings and a few Common Grackles. When taking the picture, I purposefully avoided all parts of the flock that sported other species -- I wanted a single-species flock for the picture, which I took in Cape May Point, Cape May Co., NJ, on 15 November 2009. Despite the chance that the two birds are not cowbirds, I believe that I managed to not include anything but Brown-headed Cowbirds in the picture -- what we can see of these two birds is just not enough, in my opinion, to justify identifying a second species.

One respondent's answer was precluded from being correct for the competition, as it included none of the requisite two capital letters.

Incorrect species provided as answers:
Shiny Cowbird - 2
Red-winged Blackbird - 2
Brewer's Blackbird - 1
Rusty Blackbird - 2
Rusty/Brewer's Blackbird - 1
Bronzed Cowbird - 1

The 13 of 21 providing the correct answer:
John Bissell
Kevin Kerr
Nick Komar
Ira Sanders
Tammy Sanders
Al Guarente
Mary France
Margie Joy
Barbara Deneen
Marcel Such
JOel Such
Aaron Brees
Chishun Kwong

Answer: Brown-headed Cowbird